Naturally, there was immense focus on the creative evolution of the titular star of the film Hobbit:The Desolation of Smaug: USA Today have provided a tidy 5 point overview here:
1. 'His resonance comes from a human counterpart'.
In order to realize the dragon's mannerisms, actor did motion-capture under the supervision of visual effects extraordinaire Joe Letteri. This was in order to achieve the unique facial expressions and 'deep voice'.
2. 'Smaug shows his age'.
Following on from the personality came the aged haggard body. This involved scientific precision of perfecting the physicality of Smaug's scales. Proving a tricky process, the scales had to look authentic as 'the dragon slithers through millions of coins in a confrontational chase with Bilbo'.
3. 'The dragon's mouth was a different kind of challenge'.
Where Gollum was easier to create using motion-capture in the first Hobbit movie due to his 'humanoid face', Smaug proved to be more difficult due to:
This huge jaw that goes all the way down to the back of his mouth that humans don't [have]. The equivalent jaw movement on a human to make sound like a syllable would translate into this really, over-large movement on the dragon.
4. 'He has fire in his eyes and chest'.
Smaug's menacing yellow eyes which change in accordance to his mood, reflect conversations and glow like embers when he gets angry. This also applies to his chest which glows red when preparing to expel fire.
5. 'Multicultural influence abounds in his look'.
'Letteri used a classic European feel but also that of a long, thin Asian dragon from legend' which becomes visible when he takes flight in The Hobbit: The Desolation of Smaug.
Are there any aspects which you die hard fans picked up on which is not included here?
Source: USA Today